What symbols should be used to represent amino acids in a sequence listing?

The MPEP 2412.05(d) provides guidance on the symbols to be used for amino acid representation:

• Use symbols set forth in Table 3 of WIPO Standard ST.26
• Only uppercase letters must be used
• Each symbol represents only one residue
• Use the most restrictive symbol for ambiguities

The MPEP states, “WIPO Standard ST.26, paragraph 26, specifies that all amino acids in a sequence must be represented using the symbols set forth in Table 3, above. Only uppercase letters must be used. Any symbol used to represent an amino acid is the equivalent of only one residue.” This standardization ensures consistency and clarity in sequence listings across patent applications.

To learn more:

• amino acid symbols
• sequence listing
• WIPO Standard ST.26
• ambiguity symbols